Endoscopic procedures for treating abnormal pathologies within the alimentary canal system and biliary tree (including the biliary, hepatic, and pancreatic ducts) are increasing in number. The endoscope provides access to the general area of a desired duct using direct visualization. However, the duct itself must be navigated using a catheter in conjunction with fluoroscopy and guide wires.
Catheters are known for treatment of targeted anatomical regions. Known methods and devices for using biliary catheters for accessing the biliary tree for performing catheter procedures are disclosed in Weaver et al., U.S. Pat. No. 5,397,302 and Karpiel, U.S. Pat. No. 5,320,602, the disclosures of which are herein incorporated by reference. In general, for treatment of an abnormal pathology within a patient's biliary tree, an endoscope is first introduced into the mouth of the patient. The endoscope includes a proximal end and a distal end, and has a lumen extending longitudinally between the proximal and distal ends. The endoscope is guided through the patient's alimentary tract or canal until an opening at the distal end of the endoscope is proximate the area to receive treatment. At this point, the endoscope allows other components, such as a catheter, to access the targeted area.
For visualization or treatment within the biliary tree, the distal end of the endoscope is positioned proximate to the papilla of vater leading to the common bile duct and the pancreatic duct. A catheter is guided through the lumen of the endoscope until a distal tip of the catheter emerges from the opening at the distal end of the endoscope.
The catheter may be used for accessing the biliary tree. The distal end of the catheter is guided through the orifice to the papilla of vater (located between the sphincter of oddi) leading to the common bile duct and the pancreatic duct. A guide wire may be used in conjunction with the catheter to facilitate accessing a desired location within the biliary tree. The guide wire is inserted in an opening at a proximal end of the catheter and guided through the catheter until it emerges from the distal end of the catheter.
If visualization of the common bile duct is desired, the guide wire is guided into the common bile duct. The catheter is advanced over the guide wire, as previously described, until the distal end of the catheter is positioned in the common bile duct at the desired location. The catheter is now in position for delivery of contrast media for fluoroscopic visualization of anatomical detail within the common bile duct.
Visualization may reveal selected areas within the common bile duct that require treatment. To treat the selected areas, a different catheter is typically required, necessitating a catheter exchange. A catheter exchange typically involves removing the first catheter from the endoscope over the guide wire, and advancing a second catheter over the guide wire to the desired treatment site. Thus, once the guide wire is in place relative to the targeted area, it is highly desirable to maintain the position of the guide wire during subsequent catheter procedures, including during a catheter exchange procedure. If the guide wire moves during such a procedure, the guide wire may have to be re-directed through the body ducts to the target site, which is often a difficult, time consuming, and tedious task.
In addition to performing a catheter exchange procedure, it may also be desirable to perform a guide wire exchange procedure. This may be desirable when, for example, a first guide wire is too large to fit through a desired body duct, or otherwise lacks the desired characteristics. Under these circumstances, a physician may leave the catheter in place, withdraw the first guide wire from the catheter, and insert a second guide wire through the catheter to the desired site. During this procedure, the catheter guides the guide wire to the desired site. Thus, once the catheter is positioned at a target site, it is highly desirable to maintain the position of the catheter during a guide wire exchange procedure so that the second guide wire may be guided directly to the desired site in a minimum amount of time.
To maintain the position of a guide wire and/or catheter, a physician typically must grasp the proximal end of the guide wire and/or catheter with one hand, and perform the corresponding exchange with the other. This is difficult and often results in the movement of the guide wire and/or catheter. Therefore, it would be desirable to provide a locking device whereby the physician can secure the position of the guide wire and/or catheter during an exchange procedure, thereby freeing both hands to perform other tasks.
It would also be desirable to have a tool for inserting a guide wire into a catheter. Inserting a guide wire into the guide wire lumen of a rapid exchange catheter, whether in preparing the catheter and guide wire for insertion into the endoscope or performing a guide wire exchange procedure, is often difficult due to the relatively small size of the guide wire entry slot or port. Specifically, the guide wire entry slot or port may be difficult to locate on the catheter shaft and, even after the guide wire slot or port has been located, inserting the guide wire into the guide wire lumen may be as difficult as threading a needle. Accordingly, it would be desirable to have a tool and method for assisting in the insertion of a guide wire into a catheter, particularly a rapid exchange catheter.
The present invention provides an insertion tool and method for easily inserting a guide wire into a catheter, particularly a rapid exchange catheter, for use in an endoscope. An insertion tool in accordance with an embodiment of the present invention includes a main body having a lumen sized to accommodate the catheter and a funnel-shaped extension having a funnel-shaped lumen that merges with the main lumen. The funnel-shaped lumen has a large first opening and a smaller second opening aligned with the guide wire lumen of the catheter such that, when the catheter is disposed in the main lumen, the guide wire may be easily inserted into the large opening of the funnel-shaped lumen and into the guide wire lumen of the catheter.
The catheter, as in a rapid exchange catheter, may include a longitudinal slot that provides access to the guide wire lumen, in which case the insertion tool may include a corresponding tongue or key disposed in the main lumen. Alternatively, the insertion tool may include a non-round (e.g., flat) surface that engages a similar surface on the catheter. The tongue or engaging surface is aligned with the funnel-shaped extension and the slot of the catheter to thereby maintain alignment between the funnel-shaped lumen and the slot. The insertion tool may also include a longitudinal slot in the funnel and/or main body that is aligned with the longitudinal slot of the catheter to allow removal of the guide wire from the insertion tool while the guide wire remains disposed in the guide wire lumen of the catheter.
A method of using an insertion tool in accordance with an embodiment of the present invention includes the steps of placing the insertion tool on the catheter such that the catheter extends through the main lumen and inserting the guide wire through the funnel-shaped extension of the insertion tool and into the guide wire lumen of the catheter. The insertion tool may be slidable or stationary on the catheter. If the insertion tool is slidable on the catheter, the insertion tool may be advanced along the catheter to insert a section of thereof securely into the lumen of the endoscope, preferably prior to inserting the guide wire. The section may be inserted a sufficient distance to open the valve in the lumen of the endoscope to permit unhindered longitudinal movement of the catheter through the valve. After the guide wire has been inserted into the guide wire lumen of the catheter, the guide wire may be removed from the insertion tool through a slot in the funnel-shaped extension and/or main body while the guide wire remains in place within the catheter. The insertion tool may then be removed from the lumen of the endoscope by sliding the tool proximally along the catheter.
The present invention also provides a re-insertion tool and method for re-inserting a guide wire into a channel of a catheter. The re-insertion tool is particularly useful in combination with an endoscope and a SOE catheter disposed therein. Because the endoscope may be too small to accommodate the guide wire and the catheter side-by-side, it is desirable to reintroduce the guide wire into the channel of the catheter proximal of the port of the endoscope, before advancing or retracting the catheter and/or guide wire. Specifically, with the distal portion of the guide wire disposed in the channel/guide wire lumen of the catheter distal of the port of the endoscope, and the proximal portion of the guide wire disposed adjacent to the catheter proximal of the port, the re-insertion tool may be used to re-introduce the guide wire into the channel of the catheter proximal of the port. The re-insertion tool thereby facilitates easy retraction and advancement of the catheter and/or guide wire relative to the endoscope. Preferably, the reinsertion tool has to an outside diameter greater than the inside diameter of the lumen of the endoscope. Also preferably, the lumen of the reinsertion tool has an inside diameter sized to accommodate the catheter, but less than the inside diameter of the lumen of the endoscope. The reinsertion tool may further include a keel sized to fit in the channel of the catheter.